Question

Determining aluminum content in candy: To determine the aluminum content in sour apple candy, a 5.12 g piece is mineralized by heating, dissolved in 5.00 mL concentrated sulfuric acid and then diluted to the mark in a 100.00-mL volumetric flask. To 25.00 mL volumetric flasks are added a 5.00 mL aliquot of the dissolved candy sample. To each flask, 250.0 ppm aluminum standard was added in the volumes listed below. After dilution to volume, the solution is analyzed for aluminum by graphite furnace atomic absorption spectroscopy at 309 nm. The results are shown below. Report the aluminum content of the candy. Assume all solutions prepared assume the density of water

Vol of added standard (mL), Signal (Abs)

0 , 0.214

0.100 , 0.386

0.200 , 0.554

0.300, 0.728

Answer 1

calculations for other aliqots are done in excel

	sample vol	Vol.of	[AL]std.		Final vol.	Final [AL]
	(mL)	AL Std	(ppm)		(mL)	in aliqots,ppm	Abs
S.No	Vo	V1	C1	C1V1	V2	C2=(C1V1/V2)
1	5	0.000	250.000	0.000	25.0	0.0000	0.214
2	5	0.100	250.000	25.000	25.00	1.0000	0.386
3	5	0.200	250.000	50.000	25.00	2.0000	0.554
4	5	0.300	250.000	75.000	25.00	3.0000	0.728